Conduit Arteries Research Articles

Higher Cardio-Ankle Vascular Index Values in Patients With Vestibular Neuritis May Indicate a Better Prognosis.

The presumed etiology of vestibular neuritis (VN), a sudden onset of spontaneous vertigo without auditory or cranial nerve symptoms, includes viral infections and vascular disorders. However, no clinical test for estimating vascular disorders in VN has been reported. Moreover, estimating the etiology of VN is important to predict the prognosis and select appropriate treatment. This study aimed to evaluate the cardio-ankle vascular index (CAVI), which reflects arterial stiffness and elasticity, as an additional indicator for estimating the prognosis and etiology of VN. Among 207 consecutive patients with suspected VN, 88 patients diagnosed with definite VN were enrolled. Age, initial and final percent canal paresis (CP) in the caloric test, CAVI, presence or absence of vestibular-evoked myogenic potential asymmetry, and medical history were evaluated using univariate and multivariate analyses. Patients with VN with high CAVI had a better prognosis than those with low CAVI. High CAVI was a factor for improvement in percent CP, in addition to younger age and less severe initial percent CP in the Cox proportional hazard model. CAVI can be an additional indicator for estimating the prognosis and etiology of VN. This indicator can potentially be applied to other diseases, including vascular disorders with other etiologies.

Changes in common carotid artery elasticity in solid organ recipients

Background. Cardiovascular diseases are very common among solid organ recipients. They are associated with worsening transplant outcomes. Arterial vascular wall elasticity is an important prognostic indicator and a risk marker for cardiovascular events. Noninvasive measurement of common carotid artery (CCA) elasticity may be useful in assessing cardiovascular risk in solid organ recipients.Objective: To conduct a comparative analysis of indicators of CCA elasticity in solid organ recipients and to study their relationship with factors that potentially have a negative impact on the risk of adverse events.Materials and methods. The study included 154 patients aged 10 to 75 years, including heart (n = 77), liver (n = 9), and kidney (n = 35) recipients, as well as 33 patients with end-stage heart failure waitlisted for heart transplantation (HT). In all participants, carotid artery ultrasound was performed, pulse wave velocity was measured, and CCA elasticity was calculated.Results. CCA elasticity was found to be strongly inversely correlated with age, body mass index, systolic blood pressure, renal tubular filtration rate, CCA intima media thickness, and aortic pulse wave velocity. In heart recipients, CCA elasticity was significantly lower than in liver and kidney recipients (p = 0,002) and it inversely correlated with the length of time elapsed after transplantation, which is probably associated with cardiac denervation.Conclusion. CCA elasticity calculated via noninvasive ultrasound reflects the degree of adverse effects of pathological factors on the main arteries in solid organ recipients.

Association between speckle tracking echocardiography and pressure-volume loop derived parameters at increasing levels of myocardial damage in a porcine model of acute cardiogenic shock

Abstract Background Echocardiography is a diagnostic cornerstone in acute cardiovascular care. However, the relationship between speckle tracking assessed global longitudinal strain (LS) and Doppler-based echocardiography with basic physiological markers of cardiac function derived from pressure-volume loops remains poorly elucidated, especially with increasing levels of myocardial damage. Objectives We aimed to describe the association between LS and Doppler-based echocardiography and direct measurements of central hemodynamic parameters from conductance catheter-based pressure-volume loops in an animal model with increasing left ventricular (LV) dysfunction. Methods Twelve Danish landrace pigs weighing 75-80 kg were used. All instrumentations were performed percutaneously, including placement of a conductance catheter in the LV. Progressive LV dysfunction was induced by stepwise embolization trough the left main coronary artery every three minutes until a 50% reduction in cardiac output or mixed venous saturation, compared to baseline, or a mixed venous saturation <30%. Echocardiography was performed through a subxiphoid midline incision, and was done at baseline and 90 seconds after each injection. Results With progressive LV dysfunction, mean cardiac output decreased from 5.6 l/min (SD: 0.9) to 2.1 l/min (SD: 0.9) and mean mixed venous saturation deteriorated from 61.1%(SD: 7.9) to 35.3% (SD: 6.1). Mean LS and LV outflow tract velocity time integral (LVOT VTI) declined from -13.8% (SD 3.0) to -6.1% (SD: 2.0) and 16.9 cm (SD: 2.6) to 7.8 cm (SD: 1.8), respectively (Figure 1). LS and LVOT VTI showed the strongest correlation to stroke work in unadjusted univariate regression (r2=0.53 and r2=0.49, respectively. p<0.01 for both). LS correlated significantly, but modest, with stroke volume (r2=0.46, p<0.01), end-systolic elastance (r2=0.32, p<0.01), systolic blood pressure (r2=0.37, p<0.01), ventriculo-arterial coupling(r2=0.34, p<0.01), and arterial elastance (r2=0.23, p<0.01) (Figure 2). In a multivariate regression analysis, LS showed significant correlation with stroke work, systolic blood pressure, and end-diastolic wall stress (r2=0.60, p<0.01). Conclusion In an animal model of acute progressive LV dysfunction, echocardiographic and conductance catheter-based measurements changed significantly. LS and LVOT VTI displayed the earliest and the largest alterations with increased myocardial damage and LS showed moderate correlations with contractility, arterial elastance and ventriculo-arterial coupling. This indicates that LS is a marker of overall ventricular performance.Echocardiographic changes from baselineScatter plot of LS and hemodynamics

Transcatheter-edge-to-edge-repair of functional mitral regurgitation in advanced HFrEF: the impact of intrinsic left ventricular performance on the degree of MR reduction and clinical outcome

Abstract Background Transcatheter-edge-to-edge-repair (TEER) of functional mitral regurgitation (FMR) reduces rehospitalisation and all-cause mortality in patients with HFrEF/HFmrEF. Not conclusively clarified is the interaction of pre-interventional intrinsic left ventricular (LV) function with TEER success and clinical outcome. By using the gold standard of LV contractility analysis, the invasive pressure-volume loop technique, we examined the interaction of pre-and post-interventional intrinsic LV performance with the degree of MR reduction and all-cause mortality after TEER in patients with advanced HFrEF. Methods In a prospective study of 71 patients with advanced HFrEF (median EF 26%, 22-31%) and severe FMR, we quantified different intrinsic parameters of LV performance by PV-loop analysis (single beat analysis) pre-and post-interventionally. Results In 83% of the patients a MR reduction to grad < 2 could be achieved (hospital discharge). In the ROC analysis, the best cut-off to separate medium-term survival from all-cause mortality (median FU 2.9 years) was a post-interventional regurgitation fraction (RF) < 20% (AUC 0.72, p<0.001, sensitivity 83%, specificity 60%) and a R-volume (RV) < 18ml (AUC 0,7, p=0.002, sensitivity 67%, specificity 72%). The PV-loop-derived intrinsic LV contractility (LV-endsystolic elastance, Ees), LV afterload (arterial elastance, Ea), LV-Ao-coupling (Ees/Ea), LV-mechanical efficacy (ME), PV-loop area (PVA), stroke work, Tau; end-diastolic elastance (Eed), LVEF, LVEDV, and LVESV, pre- and post-TEER, were not predictive for the extent of MR reduction acutely, after 6 months FU, and for all-cause mortality. In multivariate cox-regression analysis, only a post-interventional RF<20% (HR 0.36, p=0.017) or RV<18ml (HR 0.32, p=0.005) and the pre-interventional LV-contractile reserve (LV-CR: post-extra-systolic augmentation of LV-Ees) remained independent predictors of all-cause mortality. In a second model, we included the degree of LV-remodeling (LV-R: LVESV reduction from hospital discharge to 6 months) in the model. In addition to pre-interventional LV-CR, and RF<20%, the LV-R remains independent predictive for all-cause mortality. Conclusion In our peri-mitral-TEER LV-PV-loop study, only the extent of MR reduction and the pre-interventional LV-CR, but not the intrinsic LV performance at rest, determine the medium-term survival of patients with advanced HFrEF and FMR. TEER-mediated MR reduction itself seems not be determined by the LV performance.

Impact of collateral vessels on Fontan circulation by using 0-1 dimensional Fontan circulation model considering concepts of oxygen supply and consumption

Abstract Background/Purpose In patients with univentricular heart disease, the Fontan operation has played a significant role in improving cyanosis and reducing the volume load on the systemic ventricle. However, Fontan patients may develop various complications, and their hemodynamics may deteriorate gradually, resulting in a poor long-term survival rate. Development of collateral vessels before and/or after the Fontan operation is one of the significant problems, and the patients may suffer from advanced cyanosis and heart failure. Although recent studies about the collateral vessels by MRI showed that a significant amount of blood is flown through the collateral vessels, little is known about its effect on the Fontan circulation. Therefore, understanding the mechanism and impact of collateral vessels on the Fontan circulation is important. Methods A 0-1-dimensional Fontan circulation hemodynamic model was developed to reproduce the hemodynamic changes of the blood flow in the entire body by introducing two types of collateral vessels (VVC: veno-venous collateral, APC: aorto-pulmonary collateral) into the model considering clinical status. Also, giving various conditions by ranging catecholamine dose and introducing the concept of oxygen delivery and consumption by changing workloads, arterial and central venous oxygen saturations (SaO2 and SvO2) are predicted in the Fontan circulation models. To evaluate the cardiac function, considering the impact of collateral vessels, four representative values were examined: (1) cardiac output (CO) per minute; (2) Ees relative to arterial elastance (Ees/Ea); (3) ejection fraction; and (4) the stroke work (SW) to pressure-volume area (PVA) ratio (SW/PVA). Results SaO2 and SvO2 were less in Fontan circulations with both VVC and APC present (92% and 54%) than those without collateral vessels (96% and 62%). Also, with collateral vessels, Ees/Ea was decreased while SW/PVA was increased, leading to poor perfusion to the tissue. Regardless of the presence or absence of collateral circulation, SaO2 and SvO2, and systemic blood flow rate decreased when pulmonary vascular resistance was high. By administering catecholamine at 10 microgram/kg/min, in the presence of both VVC and APC, SvO2 was increased from 53% to 58%, while SaO2 was decreased from 92% to 88%. Conclusions The simulated results of arterial and venous blood oxygen saturations and systemic blood flow rate were well-reproduced, matching the previously reported clinical results. It is suggested that pulmonary vasodilators may be beneficial in increasing blood oxygen saturation and improving tissue perfusion, even in Fontan patients with collateral vessels. However, the catecholamine's positive effect is limited. For reproducing various conditions of Fontan circulations, it is necessary to collect actual measurement data from a variety of patients and validate the predicted value to increase the credibility of the model.Arterial and venous oxygen saturationsPressure and volume curves

The acute hemodynamic effects of sodium lactate infusion: increased cardiac output and decreased afterload in a randomized trial in pigs

Abstract Background Lactate is traditionally acknowledged as a by-product of anaerobic glucose metabolism. Recently, however, lactate has been proven to be a preferred oxidative substrate for stressed myocardium. Studies have shown that exogenous lactate infusion provides beneficial hemodynamic effects including increased cardiac output (CO). Nevertheless, the exact mechanism of action underlying the hemodynamic effects of lactate infusion has not been fully elucidated. Aim To identify the cardiovascular mechanisms behind the acute hemodynamic effects of exogenous sodium lactate infusion in an experimental model of healthy human-sized pigs. Methods We performed a randomized, assessor-blinded crossover study in eight female 60 kg pigs. In randomized order, the pigs received an infusion with 1 M sodium lactate for two hours and a control infusion with iso-osmolar and isovolumetric sodium chloride for two hours. The two infusion periods were separated by a one-hour washout period. We measured CO and pulmonary pressures hourly with a pulmonary artery catheter. A pressure-volume admittance catheter was inserted in the left ventricle to assess measures of cardiac efficiency, contractility, afterload, and preload. Hemodynamic measures as arterial blood pressure, heart rate, and mixed venous saturation (SvO2) were measured hourly as well. The study followed the principles of laboratory animal care (NIH Publication no. 85-23 revised 1985) and national and European legislations. Results Lactate levels increased by 9.9 mmol/L (95% CI 9.1 to 11.0) and CO increased by 2.0 L/min (95% CI 1.2 to 2.8) during lactate infusion as compared with the control period (figure 1). During lactate infusion, ejection fraction increased by 16.0 percentage points (95% CI 1.9 to 31.0) and heart rate by 21 bpm (95% CI 9 to 32) compared with control. Arterial elastance decreased by -1.1 mmHg/ml (95% CI -2.1 to -0.18). Lactate infusion also increased cardiac efficiency, SvO2, arterial pH, and arterial glucose concentration significantly. The infusion of lactate led to no changes in systemic arterial pressure nor pulmonary pressures including pulmonary artery wedge pressure. Also, no changes were found in left ventricle end systolic elastance (contractility). Futhermore, no change in left ventricle end-diastolic volume or -pressure (preload) were observed during lactate infusion compared with the control (figure 2). Conclusion High dose lactate infusion increased cardiac output by reducing afterload. No changes in left ventricular contractility or -preload were observed.Fig 1:Lactate concentration and COFig 2:Changes of endpoint parameters

Treatment with sacubitril/valsartan and improvement of ventricular-arterial coupling in heart failure with reduced ejection fraction

Abstract Background Treatment with the angiotensin receptor-neprilysin inhibitor sacubitril/valsartan (S/V) in patients with heart failure and reduced ejection fraction (HFrEF) reduces mortality and heart failure (HF) hospitalizations. The specific hemodynamic mechanisms underlying these beneficial effects are currently unclear. Purpose This study aimed to assess the effects of S/V treatment on left ventricular (LV) end-systolic elastance (Ees), effective arterial elastance (Ea), and the ventricular-arterial coupling ratio (Ea/Ees) in patients with HFrEF using non-invasive pressure-volume analysis. Methods 117 patients with symptomatic HF and LVEF <40% in whom treatment with S/V was initiated were enrolled in this multicenter German prospective study. We used transthoracic echocardiography with simultaneous arm-cuff blood pressure measurements for non-invasive pressure-volume loop analyses. Primary endpoints were changes in Ees, Ea, and Ea/Ees ratio after six months of S/V treatment. Results The mean age was 65 (±13) years and 30% were female. In 54.7% of the patients, the etiology of HF was ischemic, and 45.3% was non-ischemic. 58.4% had first HF diagnosis at baseline. 102 patients with complete clinical and echocardiographic data at baseline and after six months of follow-up were analyzed. Among those, 62% were on target dose of S/V. Six months of S/V treatment resulted in a significant increase of Ees (0.66 mmHg/ml, IQR [0.45;0.94] vs. 0.78 mmHg/ml [0.57;1.10], p=0.001) and decrease of Ea (1.76 mmHg/ml [1.48;2.13] vs. 1.62 mmHg/ml [1.36;1.96], p=0.014). Hence, the Ea/Ees ratio significantly improved (2.52 [1.88;4.05] vs. 1.93 [1.50;2.63], p<0.001). In addition, LV volumes and pressure improved significantly with a regression of the LV end-systolic volume (LVESV: 142 ml [115;180] vs. 96 ml [65;124]), end-diastolic volume (LVEDV: 216 ml [179;247] vs. 165 ml [132;200]) and LV end-diastolic pressure (LVEDP: 19.6 mmHg [18.2;22.4] vs. 17.8 mmHg [16.6;19.9]), p<0.001 respectively. The LVEF increased from a median of 33% (27;37) to 43% (36;49), p<0.001. NT-proBNP level decreased from (median) 1771 pg/ml [838;5211] to 724 pg/ml [300;1575] and mean 6-minute walking distance increased from 371m (±125) to 423 m (±122), p<0.001 respectively. The percentage of patients with NYHA class III changed from 25.6% to 5.9%. Conclusion In a 6-months treatment period, initiation of sacubitril/valsartan in patients with heart failure and reduced ejection fraction was associated with reduction of LV volumes, improved LV function, reduction in afterload and fewer heart failure symptoms. These new data indicate that beyond reverse LV remodeling, improvement of LV contractility and ventricular-arterial coupling may contribute to the favorable clinical outcomes on treatment with sacubitril/valsartan in chronic heart failure.

Right ventricular function in moderate-to-severe ventricular tricuspid regurgitation: Is there a pseudo-normalization of conventional echocardiographic parameters?

Abstract Background A reliable evaluation of right ventricular (RV) function in the presence of moderate-to-severe tricuspid regurgitation (m/s-TR) is of paramount importance for surgical or interventional risk stratification. Due to the significant systolic regurgitation of blood from the RV to the low-pressure right atrium, conventional echocardiographic parameters could appear normal and thus overestimate RV function (pseudo-normal). The aim of this study was to analyse and compare RV function in trace TR versus m/s-TR by the invasive pressure-volume-loop (PV-loop) technique, the gold standard of RV function analysis, with conventional echocardiographic indices in patients with the ventricular form of mild/no vs. m/s-TR. Methods The study was conducted in 134 patients with HFrEF in a post-hoc analysis (110 from the Magdeburg CRT Responder Trial, and 24 from a local CRT-optimization trial). Results The logistic regression analysis demonstrated that RV size (RV-end-diastolic volume, RVEDV) and RV function (measured as RV fractional area change, FAC), TAPSE, and lower fractional shortening (FS) of proximal the RV-outflow tract (RVOTprox) was closely associated with PV-loop-derived RV total afterload (pulmonary arterial elastance, Ea) and coupling of RV contractility (end-systolic RV elastance, Ees) to Ea (Ees/Ea) (all, p<0.001). Compared to trace TR (n=98, 73%), m/s-TR (n=36, 27%) was accompanied with significant higher total afterloads (Ea: 0.75 vs.0.41, p<0.001) and lower RV-PA coupling ratios (Ees/Ea, 0.4 vs. 0.79, p<0.001). This was associated with enlarged RVs (RVEDV: 210ml vs. 166ml), lower FAC (31% vs. 50%), TAPSE (13mm vs. 18mm), and RVOTprox (22% vs. 39%) (all p<0.001). For better comparability between trace TR and m/s-TR tertiles (T1-T3) of similar afterloads (Ea) were formed. The m/s-TR patients showed significant lower RV-PA coupling ratios than trace TR at the lower two Ea tertiles T1 (p=0.034) and T2 (p<0.001). At Ea T3 the difference was no longer significant (p=0.055). The hemodynamic data are mirrored by significant lower FACs, FS RVOTprox, and TAPSE at T1 and T2 (all p<0.05), and a nonsignificant difference at T3 in m/s-TR. In conclusion: In our cohort of HFrEF patients, echocardiographic RV function reflects very closely the hemodynamic coupling efficiency of RV contractility (Ees) to afterload (Ea) and seems independent from the extent of TR. We found no evidence for pseudo-normal or overestimated echocardiographic RV function in m/s-TR.

Abstract 13719: Minimal and Delayed Age-Related Increase of Arterial Stiffness Among Tsimane Forager-Horticulturalists

Background: Tsimane forager-farmers of the Bolivian Amazon exhibit a distinct trajectory of vascular aging, characterized by low age-related increases in BP, the lowest levels of coronary calcification ever reported, and robust VO 2 max. However, the prevalence of arterial stiffness (ArSt) in this population and its association with age and other cardiovascular risk factors are unknown. Methods: Large artery elasticity (LAE) and small artery elasticity (SAE) were measured among 491 Tsimane adults (mean age 55.3±13.0 y, 55% female) using HDI CR-2000 (Eagan, MN). Carotid-femoral pulse wave velocity (cfPWV) was assessed among 89 Tsimane (mean age 53.1±15.7 y, 54% female) using the foot-to-foot method with ECG and carotid/femoral pulse wave data. Results: Compared to previous studies from diverse urban populations, Tsimane show lower indices of ArSt: higher LAE (mean 22.79±12.21 ml/mmHg·10) and SAE (mean 7.57±4.04 ml/mmHg·100), and lower cfPWV (mean 6.34±2.1 m/s). LAE and SAE are 73% and 57% higher for Tsimane men, and 70% and 86% higher for Tsimane women, compared to age-matched US MESA adults. Tsimane demonstrate lower LAE and SAE with age, while higher cfPWV was only evident among Tsimane over 70 years (β=2.26±0.71, P =0.001; reference <40 y). Hypertension is rare in this population, but was associated with having higher ArSt. Conclusion: Tsimane forager-farmers have substantially lower levels of ArSt and fewer age-related differences in ArSt compared to more urbanized and sedentary populations. The minimal and delayed age-related increase of arterial stiffness might contribute to the very low observed levels of coronary atherosclerosis and dementia in the Tsimane.

Abstract 11994: Lithotripsy-Assisted Transcatheter Aortic Valve Implantation: An Emerging Approach to Vascular Access Issues in Severe Peripheral Arterial Disease

Introduction: Advances in minimally invasive valvular interventions like transcatheter aortic valve implantation (TAVI) allow for treatment of an increasingly older population. Severe calcific iliofemoral peripheral arterial disease (PAD) can preclude large sheath introduction necessary in TAVI. Conventional peripheral angioplasty has limited efficacy in these situations given its high-pressure dilation, which increases the risk of vascular complications. Intravascular shockwave lithotripsy (IVL) for PAD is an emerging and safe alternative for vascular access. Case Description: A 90-year-old man with severe symptomatic aortic stenosis (AS), coronary artery disease (CAD) status-post CABG and extensive PAD was referred for TAVI following balloon aortic valvuloplasty. Transthoracic echocardiogram showed severe, low-flow, low-gradient AS despite recent balloon aortic valvuloplasty. Abdominal imaging showed severe atherosclerosis and calcification of the bilateral common and external iliac arteries. Prior to TAVI, peripheral angiogram was performed, followed by IVL for a total of nine runs, each for fifteen seconds with a 7x60mm balloon to the right iliac and femoral arteries. Then, the right femoral groin sheath was upsized from six to eighteen French, followed by deployment of a 29mm Medtronic Evolute Pro+ self-expanding bioprosthetic aortic valve. Following successful TAVI, the patient was discharged home on aspirin and clopidogrel. Conclusion: IVL utilizes pulsatile mechanical shockwaves to modify plaque burden without altering arterial elasticity or structural integrity, which greatly reduces the risk for vascular complications in severely calcified arteries. The DISRUPT-PAD-III trial showed IVL was superior to percutaneous transluminal angioplasty with fewer complications in patients with calcified PAD. Therefore, IVL can be a safe alternative approach for PAD limiting vascular access in percutaneous valvular interventions.

Abstract 14318: Right Ventriculo- Arterial Coupling Assessment by High-Fidelity Hemodynamic Measurements in Patients Undergoing Left Ventricular Assist Device Implantation

Background: The changes in RV function after LVAD placement are not fully understood. RV- PA coupling, defined as the ratio of RV end-systolic to arterial elastances (E ES /E A ), offers unique insight into the cardiopulmonary unit and opportunity to address these knowledge gaps. We present early results from our study investigating RV adaptive changes after LVAD implantation by intraoperative placement of RV conductance catheters. Methods: Conductance catheter, echocardiographic, and hemodynamic data were gathered starting on the day of surgery. We used a 7Fr high-fidelity RV conductance catheter delivered through a 9Fr central venous sheath. P-V loop parameters were obtained before skin incision and after chest closure. Single- beat methods were used for E ES /E A determination. Early RVF was defined according to INTERMACS criteria. Intraoperative pre- and post-implantation echocardiographic and hemodynamic parameters were compared. Results: We present data on the first 14 patients who underwent successful placement of the RV conductance catheter. Moderate or severe RVF occurred in 3 patients (21.4%). Data are presented in the table. While overall E Es (1.2 vs 1.3, p=0.785), E A (1.1 vs 1.3, p=0.154), and RV-PA coupling (E ES /E A ratio 1.1 vs 1.0, p=0.129 ) remained unchanged, several patients underwent dramatic changes, either increase or decrease, in E ES and E A (Figure). Measures of energetic expense, such as stroke work ( SW, correlate of myocardial energy transferred) and pressure-volume area (PVA, correlate of myocardial oxygen consumption) significantly decreased after LVAD implantation. Conclusions: We have shown that RV function assessment using conductance catheters and 3D echocardiography is feasible and able to identify individual responses in RV-PA coupling after LVAD implantation. Continued accrual of data will help identify different phenotypes of RV adaptation and establish a cut-off level of RV-PA uncoupling at which RVF occurs.

Wall Properties of Elastic and Muscular Arteries in Children and Adolescents at Increased Cardiovascular Risk.

Pulse wave velocity (PWV) assessment represents a simple method to estimate arterial distensibility. At present, carotid-femoral PWV (cf-PWV) is considered the gold standard method in the non-invasive evaluation of the elastic properties of the aorta. On the other hand, the mechanical properties of muscular arteries can be evaluated on the axillo-brachial-radia axis by estimating the carotid-radial PWV (cr-PWV). While a number of studies have addressed these issues in adults, limited information is available on the respective features of cf-PWV and cr-PWV and on their modulating factors in children and adolescents at increased cardiovascular risk. The mechanical properties of the predominantly elastic (aorta) and muscular (axillo-brachial-radial axis) arteries were evaluated in a pediatric population characterized by either elevated blood pressure (BP) or excess body weight, and the main factors affecting cf-PWV and cr-PWV values in these individuals were investigated. 443 children and adolescents (median age 11.5 years, 43.3% females) were enrolled; 25% had BP values >90th percentile and 81% were excess weight. The cf-PWV values were significantly lower than the cr-PWV values: median (Q1-Q3) = 4.8 m/s (4.3-5.5) and 5.8 m/s (5.0-6.5), respectively (p < 0.001). The pubertal development (p < 0.03), systolic BP and diastolic BP z-scores (p = 0.002), heart rate (p < 0.001), and waist-to-height ratio (p < 0.005) were significantly associated with cf-PWV values. No significant association was found between BMI z-score and cf-PWV. Predictors of high cf-PWV (>95th percentile) were the heart rate (OR 1.07, 95%CI 1.04-1.10, p < 0.001) and waist-to-height ratio (OR 1.06, 95%CI 1.0-1.13, p = 0.04). The variables significantly related with cr-PWV values were diastolic BP z-score (p = 0.001), heart rate (p < 0.01), and HOMA index (p < 0.02). No significant association was found between the cr-PWV and BMI z-score or waist-to-height ratio. Systolic and diastolic BP values and central obesity are associated with aortic stiffness in a population of children and adolescents at increased cardiovascular risk. In contrast, diastolic BP, heart rate, and levels of insulin resistance appear to be related to distensibility of the upper limb vascular district.

Effects of regular exercise on vascular function with aging: Does sex matter?

Vascular aging, featuring endothelial dysfunction and large elastic artery stiffening, is a major risk factor for the development of age-associated cardiovascular diseases (CVDs). Vascular aging is largely mediated by an excessive production of reactive oxygen species (ROS) and increased inflammation leading to reduced bioavailability of the vasodilatory molecule nitric oxide and remodeling of the arterial wall. Other cellular mechanisms (i.e., mitochondrial dysfunction, impaired stress response, deregulated nutrient sensing, cellular senescence), termed "hallmarks" or "pillars" of aging, may also contribute to vascular aging. Gonadal aging, which largely impacts women but also impacts some men, modulates the vascular aging process. Regular physical activity, including both aerobic and resistance exercise, is a first-line strategy for reducing CVD risk with aging. Although exercise is an effective intervention to counter vascular aging, there is considerable variation in the vascular response to exercise training with aging. Aerobic exercise improves large elastic artery stiffening in both middle-aged/older men and women and enhances endothelial function in middle-aged/older men by reducing oxidative stress and inflammation and preserving nitric oxide bioavailability; however, similar aerobic exercise training improvements are not consistently observed in estrogen-deficient postmenopausal women. Sex differences in adaptations to exercise may be related to gonadal aging and declines in estrogen in women that influence cellular-molecular mechanisms, disconnecting favorable signaling in the vasculature induced by exercise training. The present review will summarize the current state of knowledge on vascular adaptations to regular aerobic and resistance exercise with aging, the underlying mechanisms involved, and the moderating role of biological sex.

Arterial stiffness of the aorta and iliofemoral artery and their responses to nitroglycerin administration in myocardial infarction-prone Watanabe heritable hyperlipidemic rabbits.

The role of hypercholesterolemia in arterial stiffness, which usually reflects the progression of atherosclerosis has not been fully investigated. To clarify the meaning of arterial stiffness in hypercholesterolemia, we evaluated arterial stiffness in myocardial infarction-prone Watanabe heritable hyperlipidemic (WHHLMI) rabbits by using new arterial stiffness indices of the aorta and common iliac to femoral artery. The new arterial stiffness indices of both arteries were determined by the application of the theory of cardio-ankle vascular index (CAVI) to the aorta (aBeta) and ilio-femoral artery (ifBeta). Furthermore, the responses of both indices to nitroglycerin (NTG) administration were compared between WHHHMI and normal rabbits. aBeta and ifBeta of WHHLMI and normal rabbits were measured under anesthesia. Pulse wave velocity in the whole aorta (aPWV) and ilio-femoral artery (ifPWV), blood pressure, and other parameters were measured before and after administration of NTG (50-120 μg/kg/min) every 1 for 5 min. Atherosclerotic lesions were observed in the aorta, but a little in the ilio-femoral artery in WHHLMI rabbits. Compared with normal rabbits, aBeta was significantly higher, but ifBeta was lower in WHHLMI rabbits. When NTG was administered, ifBeta decreased significantly in both groups; however, aBeta increased in normal rabbits, but remained unchanged in WHHIMI rabbits. These findings suggested that hereditary hypercholesterolemia in rabbits did not uniformly enhance arterial stiffness in elastic artery and muscular artery. The responses to NTG were also different between two arteries. The mechanism of these different responses needs further studies.

Effect of Eight Weeks of Aerobic Exercise on Selected Blood ‏Biomechanical Variables in the Bilateral Femoral Artery of Middle-aged Men

Background and Aims A sedentary lifestyle can lead to cardiovascular diseases such as atherosclerosis. Despite the use of therapeutic interventions such as angioplasty in patients with atherosclerosis, the recurrence of stenosis is possible. Rehabilitation exercises can improve the function and structure of blood vessels by improving the biomechanics of the blood flow. In this study, we aim to assess the effect of eight weeks of aerobic exercise on selected blood biomechanical variables in the bilateral femoral artery of middle-aged men up to seven days after coronary angioplasty. Methods In this quasi-experimental study, participants were 30 men with coronary angioplasty aged 45-60 years, referred to the cardiac rehabilitation clinic of Tehran Heart Hospital. They were assigned to two exercise and control groups. Their systolic and diastolic blood velocity, pressure, and intensity were first measured. The aerobic exercise program was then performed according to the American College of Sports Medicine instructions. Analysis of covariance, paired t-test, or Wilcoxon test were used based on their results. The significance level was set at 0.05. Results The resting heart rate and systolic and diastolic blood pressures were at the same level in both groups, but the maximum heart rate of the control group was lower. The results showed no significant difference between two groups in any blood variables. Conclusion The effect of aerobic exercise was not confirmed in this study, may be due to heart disease or structural changes in the arteries (increased arterial stiffness and decreased arterial elasticity, especially in peripheral arteries). To increase the effect of rehabilitation exercises on peripheral arteries rather than central arteries, more intensity and duration of exercises are recommended to achieve the desired result.

The application value of dynamic arterial elasticity in improving hemodynamic changes during fluid resuscitation in shock patients.

The application value of dynamic arterial elasticity in improving hemodynamic changes during fluid resuscitation in shock patients.

Haemodynamic effects of labetalol in isoflurane-anaesthetized dogs that received dexmedetomidine: A randomized clinical trial

ObjectiveTo test whether labetalol improved cardiovascular function in anaesthetized dogs injected with dexmedetomidine. Study designProspective, randomized, blinded, clinical trial. AnimalsA group of 20 healthy client-owned dogs undergoing ovariohysterectomy. MethodsEach dog received dexmedetomidine (5 μg kg–1) and methadone (0.2 mg kg–1) intramuscularly. General anaesthesia was induced with propofol and maintained with isoflurane in oxygen. All dogs were mechanically ventilated, and epidural anaesthesia with lidocaine was performed.Standard anaesthetic monitoring, invasive blood pressure, oesophageal Doppler and near-infrared tissue perfusion/oxygenation were applied. Peak velocity (PV), mean acceleration and stroke distance (SD) from the oesophageal Doppler were recorded. Arterial elastance (Ea) was calculated. Tissue oxygenation (rStO2) was also recorded.Prior to surgery, animals received either 0.1 mg kg–1 of labetalol intravenously (IV) over 60 seconds or the equivalent volume of saline. Data were recorded for 20 minutes.Age, weight and propofol dose were compared with a Wilcoxon rank-sum test. The effects of time, treatment and their interaction with haemodynamic and perfusion variables were analysed with mixed-effect models and Tukey’s post hoc tests. ResultsSignificant effects of the interaction between treatment and time were observed whereby heart rate (HR) was higher in dogs given labetalol (p = 0.01), whereas arterial blood pressure and Ea were lower (p < 0.01). Similarly, PV, SD and rStO2 were higher in the labetalol group, and significant effects were detected for the interaction between treatment and time (p < 0.01). Conclusions and clinical relevanceLabetalol at a dose of 0.1 mg kg–1 IV in dogs under general anaesthesia and administered a pre-anaesthetic medication of dexmedetomidine produced mild vasodilation (reduction of Ea), resulting in an increase in HR and left ventricular outflow. Although labetalol could be an effective option to achieve haemodynamic optimization after dexmedetomidine-induced vasoconstriction, future studies are needed to assess long-term effects.

Due Diligence of a Diastolic Index as a Prognostic Factor in Heart Failure with Preserved Ejection Fraction.

Of the existing non-invasive diastolic indices, none consider arterial load. This article reveals points of caution for determining the diastolic prognostic index using a novel index of vascular resistance-integrated diastolic function in old, real-world patients with heart failure with preserved ejection fraction (HFpEF) in Japan. This index represents the ratio of left ventricular diastolic elastance (Ed) to arterial elastance (Ea), where Ed/Ea = (E/e')/(0.9 × systolic blood pressure), showing a relative ratio of left atrial filling pressure to left ventricular end-systolic pressure. The role of hemodynamic prognostic factors related to diastolic function, such as Ed/Ea, may differ according to the clinical endpoint, follow-up duration, and sex. In HFpEF patients with heterogenous cardiac structure and function, an assessment using a serial echocardiographic diastolic index in clinical care can provide an accurate prognosis.

Enzootic calcinosis in Toggenburg goats in New Zealand

ABSTRACTCase historyNecropsies on Toggenburg goats culled from a small farm in the Manawatū district of New Zealand, performed at Massey University (Palmerston North, NZ) over a period of 29 years (1991–2019), revealed soft tissue mineralisation, particularly of cardiovascular tissues. The farm spans 10 acres and runs between 15 and 30 Toggenburg goats. The goats are predominantly on pasture comprising a variety of types.Pathological findingsNecropsies were performed on all adult goats (n = 45) that died or were euthanised. Histopathology was performed on 42 goats (93%), of which 33 (73%) included sufficient tissues diagnostically relevant to soft tissue mineralisation. The most significant gross findings were in various arteries, with the aorta most commonly affected, followed by the heart and lungs. The aortic intima showed prominent, multifocal to coalescing, raised, wrinkled, white plaques. Microscopically there were multiphasic lesions of mineralisation, chondroid, and osseous metaplasia in the elastic arteries, aorta, heart and lungs. A lumbar vertebra from one goat had prominent, basophilic, fibrillar, tangled matrix lining Haversian canals and lamellae.Laboratory findingsBlood samples were collected from 15 adult goats in the affected herd and from 10 adult Toggenburg goats from an unaffected herd. Samples were collected by jugular venipuncture at 2-month intervals for 12 months (April 2018–March 2019). Concentrations of calcium, phosphorus, 25-hydroxyvitamin D2 and D3 (25OHD2, 25OHD3) in serum were analysed. The concentration of total 25OHD in serum was 34.2 (95% CI = 18.9–49.4) nmol/L (p < 0.001) higher in goats from the affected herd than in goats from the unaffected herd. Serum 25OHD2 concentration was 46.2 (95% CI = 39.2–53.2) nmol/L higher (p < 0.001) in goats from the affected herd compared to the unaffected herd. Serum Ca concentrations in affected goats were 0.101 (95% CI = 0.005–0.196) mmol/L higher (p = 0.039) than unaffected goats, but remained within the reference range. There was no evidence of a difference in serum 25OHD3 and P concentration between the herds.Vegetation surveyAll paddocks on the property were surveyed every 2 months along evenly spaced line transects, and then further traversed perpendicularly to form a grid. No known calcinogenic species were identified. Known plant sources of vitamin D identified on the farm included mushrooms (species not defined), Dactylis glomerata, lichen, pine pollen, and algae.DiagnosisSoft tissue mineralisation and enzootic calcinosis.Clinical relevanceVeterinarians are alerted to the possibility of either enzootic calcinosis in goats and the potential occurrence of calcinogenic plants in New Zealand; or chronic vitamin D toxicosis of non-plant origin.

Exercise training and vascular heterogeneity in db/db mice: evidence for regional- and duration-dependent effects.

Exercise training (ET) has several health benefits; however, our understanding of regional adaptations to ET is limited. We examined the functional and molecular adaptations to short- and long-term ET in elastic and muscular conduit arteries of db/db mice in relation to changes in cardiovascular risk factors. Diabetic mice and their controls were exercised at moderate intensity for 4 or 8weeks. The vasodilatory and contractile responses of thoracic aortae and femoral arteries isolated from the same animals were examined. Blood and aortic samples were used to measure hyperglycemia, oxidative stress, inflammation, dyslipidemia, protein expression of SOD isoforms, COX, eNOS, and Akt. Short-term ET improved nitric oxide (NO) mediated vasorelaxation in the aortae and femoral arteries of db/db mice in parallel with increased SOD2 and SOD3 expression, reduced oxidative stress and triglycerides, and independent of weight loss, glycemia, or inflammation. Long-term ET reduced body weight in parallel with reduced systemic inflammation and improved insulin sensitivity along with increased SOD1, Akt, and eNOS expression and improved NO vasorelaxation. Exercise did not restore NOS- and COX-independent vasodilatation in femoral arteries, nor did it mitigate the hypercontractility in the aortae of db/db mice; rather ET transiently increased contractility in association with upregulated COX-2. Long-term ET differentially affected the aortae and femoral arteries contractile responses. ET improved NO-mediated vasodilation in both arteries likely due to collective systemic effects. ET did not mitigate all diabetes-induced vasculopathies. Optimization of the ET regimen can help develop comprehensive management of type 2 diabetes.